Trade Names:Zemplar- capsules 1 mcg- capsules 2 mcg- capsules 4 mcg- injection 2 mcg/mL- injection 5 mcg/mL
Synthetic analog of calcitriol, the metabolically active form of vitamin D. Binds to vitamin D receptor, which results in selective activation of vitamin D responsive pathways; reduces parathyroid hormone (PTH) levels by inhibiting PTH synthesis and secretion.
Well absorbed after oral administration; bioavailability is approximately 72%. T max is 3 h. Food delays rate but not extent of absorption.
Protein binding is more than 99.8%. Vd is 44 to 46 L (oral dose; chronic kidney disease [CKD] stage 3 to 4) and 31 to 35 L (IV dose; CKD stage 5).
Extensively metabolized by multiple hepatic and nonhepatic enzymes, including CYP3A4.
Eliminated primarily by biliary excretion; approximately 63% recovered in feces following IV dose and 70% following oral dose (2% as unchanged drug), 18% to 19% in urine. The t ½ is about 17 h (CKD stage 3); 20 h (CKD stage 4); 13.9 h (CKD stage 5-hemodialysis); and 15.4 h (CKD stage 5-peritoneal dialysis).
Prevention and treatment of secondary hyperparathyroidism associated with chronic CKD stage 3 and 4 (oral), and stage 5 (IV).
Evidence of vitamin D toxicity; hypercalcemia; hypersensitivity to any component of the product.
IV Initial : 0.04 to 0.1 mcg/kg no more frequently than every other day during dialysis. Increase dose by 2 to 4 mcg at 2- to 4-wk intervals if satisfactory response is not observed. Doses may need to be decreased as PTH levels decrease. Dose titration : The following dose titrations are suggested: PTH level decreased less than 30%, is the same, or is increasing: increase dose; PTH level decreased 30% to 60%: maintain dose; PTH level decreased more than 60%: decrease dose; PTH level is 1.5 to 3 times upper limit of normal: maintain dose.Adults
PO Initial : Based on baseline intact parathyroid hormone (iPTH) levels. If baseline iPTH less than 500 pg/mL: 1 mcg daily or 2 mcg 3 times/wk; if baseline iPTH more than 500 pg/mL: 2 mcg daily or 4 mcg 3 times/wk. Dose titration : The following dose titrations are suggested at 2- to 4-wk intervals: iPTH level decreased less than 30%, is the same, or is increasing: increase dose by 1 mcg daily or 2 mcg 3 times/wk; iPTH level decreased 30% to 60%: maintain dose; iPTH level decreased more than 60% or iPTH is less than 60 pg/mL: decrease dose by 1 mcg daily or 2 mcg 3 times/wk. If patient is taking the lowest dose on the daily regimen and a dose reduction is needed, the dose can be decreased to 1 mcg 3 times/wk.
Store capsules and injection at controlled room temperature (59° to 86°F).
Digitalis toxicity is potentiated by hypercalcemia of any cause; therefore, use paricalcitol with caution in patients receiving a digitalis compound.Drugs that impair absorption of fat-soluble vitamins (eg, cholestyramine)
Paricalcitol absorption may be impaired, decreasing the efficacy.Strong inhibitors of CYP3A4 (eg, atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, voriconazole)
Paricalcitol plasma concentrations may be elevated, increasing the risk of toxicity.
None well documented.
Cardiomyopathy, CHF, hypertension, hypotension, MI, palpitation, postural hypotension, syncope (at least 2%).
Asthenia, depression, dizziness, headache, insomnia, light-headedness, neuropathy, vertigo (at least 2%).
Pruritus, rash, skin hypertrophy, skin ulcer, vesiculobullous rash (at least 2%).
Amblyopia, epistaxis, pharyngitis, retinal disorder, rhinitis (at least 2%).
Constipation, diarrhea, dry mouth, dyspepsia, gastritis, gastroenteritis, GI bleeding, nausea, rectal disorder, vomiting (at least 2%); taste perversion (postmarketing).
Abnormal kidney function, UTI (at least 2%).
Ecchymosis, hypervolemia (at least 2%).
Acidosis, dehydration, edema, gout, hyperkalemia, hyperphosphatemia, hypoglycemia, hypokalemia, uremia (at least 2%).
Arthritis, back pain, leg cramps, myalgia (at least 2%).
Bronchitis, increased cough, pneumonia, sinusitis (at least 2%).
Abdominal pain, accidental injury, allergic reaction, bacterial infection, chest pain, chills, cyst, feeling unwell, fever, flu syndrome, fungal infection, infection, pain, sepsis, viral infection (at least 2%); allergic reactions including facial and oral edema, pruritus, rash, urticaria (postmarketing).
Monitor serum calcium and phosphorous levels closely (eg, twice weekly) during dose adjustments and at least monthly once maintenance dose is established. Reduce dose or interrupt therapy if clinically significant hypercalcemia or a Ca × P product more than 75 is noted. Measure serum or plasma PTH using iPTH assay q 3 mo.Oral
Monitor serum calcium, serum phosphorous, and serum or plasma iPTH at least q 2 wk for 3 mo after initiating therapy or following dose adjustments, then monthly for 3 mo, and q 3 mo thereafter. Closely monitor serum calcium and iPTH levels during coadministration of strong CYP3A inhibitors.
Category C .
Safety and efficacy of injection not established for patients younger than 5 yr of age. Safety and efficacy of capsules not established.
No differences in safety and efficacy observed between patients older than 65 years of age and younger patients.
To avoid hypercalcemia, withhold pharmacologic doses of vitamin D and its derivatives during treatment with paricalcitol.
Hypercalcemia, hypercalciuria, hyperphosphatemia, oversuppression of parathyroid hormone.
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